1# Select 32 or 64 bit 2config 64BIT 3 bool "64-bit kernel" if ARCH = "x86" 4 default ARCH != "i386" 5 ---help--- 6 Say yes to build a 64-bit kernel - formerly known as x86_64 7 Say no to build a 32-bit kernel - formerly known as i386 8 9config X86_32 10 def_bool y 11 depends on !64BIT 12 select CLKSRC_I8253 13 select HAVE_UID16 14 15config X86_64 16 def_bool y 17 depends on 64BIT 18 select X86_DEV_DMA_OPS 19 select ARCH_USE_CMPXCHG_LOCKREF 20 21### Arch settings 22config X86 23 def_bool y 24 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS 25 select HAVE_AOUT if X86_32 26 select HAVE_UNSTABLE_SCHED_CLOCK 27 select ARCH_SUPPORTS_NUMA_BALANCING 28 select ARCH_WANTS_PROT_NUMA_PROT_NONE 29 select HAVE_IDE 30 select HAVE_OPROFILE 31 select HAVE_PCSPKR_PLATFORM 32 select HAVE_PERF_EVENTS 33 select HAVE_IOREMAP_PROT 34 select HAVE_KPROBES 35 select HAVE_MEMBLOCK 36 select HAVE_MEMBLOCK_NODE_MAP 37 select ARCH_DISCARD_MEMBLOCK 38 select ARCH_WANT_OPTIONAL_GPIOLIB 39 select ARCH_WANT_FRAME_POINTERS 40 select HAVE_DMA_ATTRS 41 select HAVE_DMA_CONTIGUOUS if !SWIOTLB 42 select HAVE_KRETPROBES 43 select HAVE_OPTPROBES 44 select HAVE_KPROBES_ON_FTRACE 45 select HAVE_FTRACE_MCOUNT_RECORD 46 select HAVE_FENTRY if X86_64 47 select HAVE_C_RECORDMCOUNT 48 select HAVE_DYNAMIC_FTRACE 49 select HAVE_DYNAMIC_FTRACE_WITH_REGS 50 select HAVE_FUNCTION_TRACER 51 select HAVE_FUNCTION_GRAPH_TRACER 52 select HAVE_FUNCTION_GRAPH_FP_TEST 53 select HAVE_FUNCTION_TRACE_MCOUNT_TEST 54 select HAVE_SYSCALL_TRACEPOINTS 55 select SYSCTL_EXCEPTION_TRACE 56 select HAVE_KVM 57 select HAVE_ARCH_KGDB 58 select HAVE_ARCH_TRACEHOOK 59 select HAVE_GENERIC_DMA_COHERENT if X86_32 60 select HAVE_EFFICIENT_UNALIGNED_ACCESS 61 select USER_STACKTRACE_SUPPORT 62 select HAVE_REGS_AND_STACK_ACCESS_API 63 select HAVE_DMA_API_DEBUG 64 select HAVE_KERNEL_GZIP 65 select HAVE_KERNEL_BZIP2 66 select HAVE_KERNEL_LZMA 67 select HAVE_KERNEL_XZ 68 select HAVE_KERNEL_LZO 69 select HAVE_KERNEL_LZ4 70 select HAVE_HW_BREAKPOINT 71 select HAVE_MIXED_BREAKPOINTS_REGS 72 select PERF_EVENTS 73 select HAVE_PERF_EVENTS_NMI 74 select HAVE_PERF_REGS 75 select HAVE_PERF_USER_STACK_DUMP 76 select HAVE_DEBUG_KMEMLEAK 77 select ANON_INODES 78 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 79 select HAVE_CMPXCHG_LOCAL 80 select HAVE_CMPXCHG_DOUBLE 81 select HAVE_ARCH_KMEMCHECK 82 select HAVE_USER_RETURN_NOTIFIER 83 select ARCH_BINFMT_ELF_RANDOMIZE_PIE 84 select HAVE_ARCH_JUMP_LABEL 85 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE 86 select SPARSE_IRQ 87 select GENERIC_FIND_FIRST_BIT 88 select GENERIC_IRQ_PROBE 89 select GENERIC_PENDING_IRQ if SMP 90 select GENERIC_IRQ_SHOW 91 select GENERIC_CLOCKEVENTS_MIN_ADJUST 92 select IRQ_FORCED_THREADING 93 select USE_GENERIC_SMP_HELPERS if SMP 94 select HAVE_BPF_JIT if X86_64 95 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 96 select CLKEVT_I8253 97 select ARCH_HAVE_NMI_SAFE_CMPXCHG 98 select GENERIC_IOMAP 99 select DCACHE_WORD_ACCESS 100 select GENERIC_SMP_IDLE_THREAD 101 select ARCH_WANT_IPC_PARSE_VERSION if X86_32 102 select HAVE_ARCH_SECCOMP_FILTER 103 select BUILDTIME_EXTABLE_SORT 104 select GENERIC_CMOS_UPDATE 105 select HAVE_ARCH_SOFT_DIRTY 106 select CLOCKSOURCE_WATCHDOG 107 select GENERIC_CLOCKEVENTS 108 select ARCH_CLOCKSOURCE_DATA if X86_64 109 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) 110 select GENERIC_TIME_VSYSCALL if X86_64 111 select KTIME_SCALAR if X86_32 112 select GENERIC_STRNCPY_FROM_USER 113 select GENERIC_STRNLEN_USER 114 select HAVE_CONTEXT_TRACKING if X86_64 115 select HAVE_IRQ_TIME_ACCOUNTING 116 select VIRT_TO_BUS 117 select MODULES_USE_ELF_REL if X86_32 118 select MODULES_USE_ELF_RELA if X86_64 119 select CLONE_BACKWARDS if X86_32 120 select ARCH_USE_BUILTIN_BSWAP 121 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION 122 select OLD_SIGACTION if X86_32 123 select COMPAT_OLD_SIGACTION if IA32_EMULATION 124 select RTC_LIB 125 select HAVE_DEBUG_STACKOVERFLOW 126 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 127 128config INSTRUCTION_DECODER 129 def_bool y 130 depends on KPROBES || PERF_EVENTS || UPROBES 131 132config OUTPUT_FORMAT 133 string 134 default "elf32-i386" if X86_32 135 default "elf64-x86-64" if X86_64 136 137config ARCH_DEFCONFIG 138 string 139 default "arch/x86/configs/i386_defconfig" if X86_32 140 default "arch/x86/configs/x86_64_defconfig" if X86_64 141 142config LOCKDEP_SUPPORT 143 def_bool y 144 145config STACKTRACE_SUPPORT 146 def_bool y 147 148config HAVE_LATENCYTOP_SUPPORT 149 def_bool y 150 151config MMU 152 def_bool y 153 154config SBUS 155 bool 156 157config NEED_DMA_MAP_STATE 158 def_bool y 159 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG 160 161config NEED_SG_DMA_LENGTH 162 def_bool y 163 164config GENERIC_ISA_DMA 165 def_bool y 166 depends on ISA_DMA_API 167 168config GENERIC_BUG 169 def_bool y 170 depends on BUG 171 select GENERIC_BUG_RELATIVE_POINTERS if X86_64 172 173config GENERIC_BUG_RELATIVE_POINTERS 174 bool 175 176config GENERIC_HWEIGHT 177 def_bool y 178 179config ARCH_MAY_HAVE_PC_FDC 180 def_bool y 181 depends on ISA_DMA_API 182 183config RWSEM_XCHGADD_ALGORITHM 184 def_bool y 185 186config GENERIC_CALIBRATE_DELAY 187 def_bool y 188 189config ARCH_HAS_CPU_RELAX 190 def_bool y 191 192config ARCH_HAS_CACHE_LINE_SIZE 193 def_bool y 194 195config ARCH_HAS_CPU_AUTOPROBE 196 def_bool y 197 198config HAVE_SETUP_PER_CPU_AREA 199 def_bool y 200 201config NEED_PER_CPU_EMBED_FIRST_CHUNK 202 def_bool y 203 204config NEED_PER_CPU_PAGE_FIRST_CHUNK 205 def_bool y 206 207config ARCH_HIBERNATION_POSSIBLE 208 def_bool y 209 210config ARCH_SUSPEND_POSSIBLE 211 def_bool y 212 213config ARCH_WANT_HUGE_PMD_SHARE 214 def_bool y 215 216config ARCH_WANT_GENERAL_HUGETLB 217 def_bool y 218 219config ZONE_DMA32 220 bool 221 default X86_64 222 223config AUDIT_ARCH 224 bool 225 default X86_64 226 227config ARCH_SUPPORTS_OPTIMIZED_INLINING 228 def_bool y 229 230config ARCH_SUPPORTS_DEBUG_PAGEALLOC 231 def_bool y 232 233config HAVE_INTEL_TXT 234 def_bool y 235 depends on INTEL_IOMMU && ACPI 236 237config X86_32_SMP 238 def_bool y 239 depends on X86_32 && SMP 240 241config X86_64_SMP 242 def_bool y 243 depends on X86_64 && SMP 244 245config X86_HT 246 def_bool y 247 depends on SMP 248 249config X86_32_LAZY_GS 250 def_bool y 251 depends on X86_32 && !CC_STACKPROTECTOR 252 253config ARCH_HWEIGHT_CFLAGS 254 string 255 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32 256 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64 257 258config ARCH_CPU_PROBE_RELEASE 259 def_bool y 260 depends on HOTPLUG_CPU 261 262config ARCH_SUPPORTS_UPROBES 263 def_bool y 264 265source "init/Kconfig" 266source "kernel/Kconfig.freezer" 267 268menu "Processor type and features" 269 270config ZONE_DMA 271 bool "DMA memory allocation support" if EXPERT 272 default y 273 help 274 DMA memory allocation support allows devices with less than 32-bit 275 addressing to allocate within the first 16MB of address space. 276 Disable if no such devices will be used. 277 278 If unsure, say Y. 279 280config SMP 281 bool "Symmetric multi-processing support" 282 ---help--- 283 This enables support for systems with more than one CPU. If you have 284 a system with only one CPU, like most personal computers, say N. If 285 you have a system with more than one CPU, say Y. 286 287 If you say N here, the kernel will run on single and multiprocessor 288 machines, but will use only one CPU of a multiprocessor machine. If 289 you say Y here, the kernel will run on many, but not all, 290 singleprocessor machines. On a singleprocessor machine, the kernel 291 will run faster if you say N here. 292 293 Note that if you say Y here and choose architecture "586" or 294 "Pentium" under "Processor family", the kernel will not work on 486 295 architectures. Similarly, multiprocessor kernels for the "PPro" 296 architecture may not work on all Pentium based boards. 297 298 People using multiprocessor machines who say Y here should also say 299 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power 300 Management" code will be disabled if you say Y here. 301 302 See also <file:Documentation/x86/i386/IO-APIC.txt>, 303 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at 304 <http://www.tldp.org/docs.html#howto>. 305 306 If you don't know what to do here, say N. 307 308config X86_X2APIC 309 bool "Support x2apic" 310 depends on X86_LOCAL_APIC && X86_64 && IRQ_REMAP 311 ---help--- 312 This enables x2apic support on CPUs that have this feature. 313 314 This allows 32-bit apic IDs (so it can support very large systems), 315 and accesses the local apic via MSRs not via mmio. 316 317 If you don't know what to do here, say N. 318 319config X86_MPPARSE 320 bool "Enable MPS table" if ACPI || SFI 321 default y 322 depends on X86_LOCAL_APIC 323 ---help--- 324 For old smp systems that do not have proper acpi support. Newer systems 325 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it 326 327config X86_BIGSMP 328 bool "Support for big SMP systems with more than 8 CPUs" 329 depends on X86_32 && SMP 330 ---help--- 331 This option is needed for the systems that have more than 8 CPUs 332 333config GOLDFISH 334 def_bool y 335 depends on X86_GOLDFISH 336 337if X86_32 338config X86_EXTENDED_PLATFORM 339 bool "Support for extended (non-PC) x86 platforms" 340 default y 341 ---help--- 342 If you disable this option then the kernel will only support 343 standard PC platforms. (which covers the vast majority of 344 systems out there.) 345 346 If you enable this option then you'll be able to select support 347 for the following (non-PC) 32 bit x86 platforms: 348 Goldfish (Android emulator) 349 AMD Elan 350 NUMAQ (IBM/Sequent) 351 RDC R-321x SoC 352 SGI 320/540 (Visual Workstation) 353 STA2X11-based (e.g. Northville) 354 Summit/EXA (IBM x440) 355 Unisys ES7000 IA32 series 356 Moorestown MID devices 357 358 If you have one of these systems, or if you want to build a 359 generic distribution kernel, say Y here - otherwise say N. 360endif 361 362if X86_64 363config X86_EXTENDED_PLATFORM 364 bool "Support for extended (non-PC) x86 platforms" 365 default y 366 ---help--- 367 If you disable this option then the kernel will only support 368 standard PC platforms. (which covers the vast majority of 369 systems out there.) 370 371 If you enable this option then you'll be able to select support 372 for the following (non-PC) 64 bit x86 platforms: 373 Numascale NumaChip 374 ScaleMP vSMP 375 SGI Ultraviolet 376 377 If you have one of these systems, or if you want to build a 378 generic distribution kernel, say Y here - otherwise say N. 379endif 380# This is an alphabetically sorted list of 64 bit extended platforms 381# Please maintain the alphabetic order if and when there are additions 382config X86_NUMACHIP 383 bool "Numascale NumaChip" 384 depends on X86_64 385 depends on X86_EXTENDED_PLATFORM 386 depends on NUMA 387 depends on SMP 388 depends on X86_X2APIC 389 depends on PCI_MMCONFIG 390 ---help--- 391 Adds support for Numascale NumaChip large-SMP systems. Needed to 392 enable more than ~168 cores. 393 If you don't have one of these, you should say N here. 394 395config X86_VSMP 396 bool "ScaleMP vSMP" 397 select HYPERVISOR_GUEST 398 select PARAVIRT 399 depends on X86_64 && PCI 400 depends on X86_EXTENDED_PLATFORM 401 depends on SMP 402 ---help--- 403 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is 404 supposed to run on these EM64T-based machines. Only choose this option 405 if you have one of these machines. 406 407config X86_UV 408 bool "SGI Ultraviolet" 409 depends on X86_64 410 depends on X86_EXTENDED_PLATFORM 411 depends on NUMA 412 depends on X86_X2APIC 413 ---help--- 414 This option is needed in order to support SGI Ultraviolet systems. 415 If you don't have one of these, you should say N here. 416 417# Following is an alphabetically sorted list of 32 bit extended platforms 418# Please maintain the alphabetic order if and when there are additions 419 420config X86_GOLDFISH 421 bool "Goldfish (Virtual Platform)" 422 depends on X86_32 423 depends on X86_EXTENDED_PLATFORM 424 ---help--- 425 Enable support for the Goldfish virtual platform used primarily 426 for Android development. Unless you are building for the Android 427 Goldfish emulator say N here. 428 429config X86_INTEL_CE 430 bool "CE4100 TV platform" 431 depends on PCI 432 depends on PCI_GODIRECT 433 depends on X86_32 434 depends on X86_EXTENDED_PLATFORM 435 select X86_REBOOTFIXUPS 436 select OF 437 select OF_EARLY_FLATTREE 438 select IRQ_DOMAIN 439 ---help--- 440 Select for the Intel CE media processor (CE4100) SOC. 441 This option compiles in support for the CE4100 SOC for settop 442 boxes and media devices. 443 444config X86_WANT_INTEL_MID 445 bool "Intel MID platform support" 446 depends on X86_32 447 depends on X86_EXTENDED_PLATFORM 448 ---help--- 449 Select to build a kernel capable of supporting Intel MID platform 450 systems which do not have the PCI legacy interfaces (Moorestown, 451 Medfield). If you are building for a PC class system say N here. 452 453if X86_WANT_INTEL_MID 454 455config X86_INTEL_MID 456 bool 457 458config X86_MDFLD 459 bool "Medfield MID platform" 460 depends on PCI 461 depends on PCI_GOANY 462 depends on X86_IO_APIC 463 select X86_INTEL_MID 464 select SFI 465 select DW_APB_TIMER 466 select APB_TIMER 467 select I2C 468 select SPI 469 select INTEL_SCU_IPC 470 select X86_PLATFORM_DEVICES 471 select MFD_INTEL_MSIC 472 ---help--- 473 Medfield is Intel's Low Power Intel Architecture (LPIA) based Moblin 474 Internet Device(MID) platform. 475 Unlike standard x86 PCs, Medfield does not have many legacy devices 476 nor standard legacy replacement devices/features. e.g. Medfield does 477 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports. 478 479endif 480 481config X86_INTEL_LPSS 482 bool "Intel Low Power Subsystem Support" 483 depends on ACPI 484 select COMMON_CLK 485 select PINCTRL 486 ---help--- 487 Select to build support for Intel Low Power Subsystem such as 488 found on Intel Lynxpoint PCH. Selecting this option enables 489 things like clock tree (common clock framework) and pincontrol 490 which are needed by the LPSS peripheral drivers. 491 492config X86_RDC321X 493 bool "RDC R-321x SoC" 494 depends on X86_32 495 depends on X86_EXTENDED_PLATFORM 496 select M486 497 select X86_REBOOTFIXUPS 498 ---help--- 499 This option is needed for RDC R-321x system-on-chip, also known 500 as R-8610-(G). 501 If you don't have one of these chips, you should say N here. 502 503config X86_32_NON_STANDARD 504 bool "Support non-standard 32-bit SMP architectures" 505 depends on X86_32 && SMP 506 depends on X86_EXTENDED_PLATFORM 507 ---help--- 508 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, 509 STA2X11, default subarchitectures. It is intended for a generic 510 binary kernel. If you select them all, kernel will probe it 511 one by one and will fallback to default. 512 513# Alphabetically sorted list of Non standard 32 bit platforms 514 515config X86_NUMAQ 516 bool "NUMAQ (IBM/Sequent)" 517 depends on X86_32_NON_STANDARD 518 depends on PCI 519 select NUMA 520 select X86_MPPARSE 521 ---help--- 522 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent) 523 NUMA multiquad box. This changes the way that processors are 524 bootstrapped, and uses Clustered Logical APIC addressing mode instead 525 of Flat Logical. You will need a new lynxer.elf file to flash your 526 firmware with - send email to <Martin.Bligh@us.ibm.com>. 527 528config X86_SUPPORTS_MEMORY_FAILURE 529 def_bool y 530 # MCE code calls memory_failure(): 531 depends on X86_MCE 532 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: 533 depends on !X86_NUMAQ 534 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: 535 depends on X86_64 || !SPARSEMEM 536 select ARCH_SUPPORTS_MEMORY_FAILURE 537 538config X86_VISWS 539 bool "SGI 320/540 (Visual Workstation)" 540 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT 541 depends on X86_32_NON_STANDARD 542 ---help--- 543 The SGI Visual Workstation series is an IA32-based workstation 544 based on SGI systems chips with some legacy PC hardware attached. 545 546 Say Y here to create a kernel to run on the SGI 320 or 540. 547 548 A kernel compiled for the Visual Workstation will run on general 549 PCs as well. See <file:Documentation/sgi-visws.txt> for details. 550 551config STA2X11 552 bool "STA2X11 Companion Chip Support" 553 depends on X86_32_NON_STANDARD && PCI 554 select X86_DEV_DMA_OPS 555 select X86_DMA_REMAP 556 select SWIOTLB 557 select MFD_STA2X11 558 select ARCH_REQUIRE_GPIOLIB 559 default n 560 ---help--- 561 This adds support for boards based on the STA2X11 IO-Hub, 562 a.k.a. "ConneXt". The chip is used in place of the standard 563 PC chipset, so all "standard" peripherals are missing. If this 564 option is selected the kernel will still be able to boot on 565 standard PC machines. 566 567config X86_SUMMIT 568 bool "Summit/EXA (IBM x440)" 569 depends on X86_32_NON_STANDARD 570 ---help--- 571 This option is needed for IBM systems that use the Summit/EXA chipset. 572 In particular, it is needed for the x440. 573 574config X86_ES7000 575 bool "Unisys ES7000 IA32 series" 576 depends on X86_32_NON_STANDARD && X86_BIGSMP 577 ---help--- 578 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is 579 supposed to run on an IA32-based Unisys ES7000 system. 580 581config X86_32_IRIS 582 tristate "Eurobraille/Iris poweroff module" 583 depends on X86_32 584 ---help--- 585 The Iris machines from EuroBraille do not have APM or ACPI support 586 to shut themselves down properly. A special I/O sequence is 587 needed to do so, which is what this module does at 588 kernel shutdown. 589 590 This is only for Iris machines from EuroBraille. 591 592 If unused, say N. 593 594config SCHED_OMIT_FRAME_POINTER 595 def_bool y 596 prompt "Single-depth WCHAN output" 597 depends on X86 598 ---help--- 599 Calculate simpler /proc/<PID>/wchan values. If this option 600 is disabled then wchan values will recurse back to the 601 caller function. This provides more accurate wchan values, 602 at the expense of slightly more scheduling overhead. 603 604 If in doubt, say "Y". 605 606menuconfig HYPERVISOR_GUEST 607 bool "Linux guest support" 608 ---help--- 609 Say Y here to enable options for running Linux under various hyper- 610 visors. This option enables basic hypervisor detection and platform 611 setup. 612 613 If you say N, all options in this submenu will be skipped and 614 disabled, and Linux guest support won't be built in. 615 616if HYPERVISOR_GUEST 617 618config PARAVIRT 619 bool "Enable paravirtualization code" 620 ---help--- 621 This changes the kernel so it can modify itself when it is run 622 under a hypervisor, potentially improving performance significantly 623 over full virtualization. However, when run without a hypervisor 624 the kernel is theoretically slower and slightly larger. 625 626config PARAVIRT_DEBUG 627 bool "paravirt-ops debugging" 628 depends on PARAVIRT && DEBUG_KERNEL 629 ---help--- 630 Enable to debug paravirt_ops internals. Specifically, BUG if 631 a paravirt_op is missing when it is called. 632 633config PARAVIRT_SPINLOCKS 634 bool "Paravirtualization layer for spinlocks" 635 depends on PARAVIRT && SMP 636 select UNINLINE_SPIN_UNLOCK 637 ---help--- 638 Paravirtualized spinlocks allow a pvops backend to replace the 639 spinlock implementation with something virtualization-friendly 640 (for example, block the virtual CPU rather than spinning). 641 642 Unfortunately the downside is an up to 5% performance hit on 643 native kernels, with various workloads. 644 645 If you are unsure how to answer this question, answer N. 646 647source "arch/x86/xen/Kconfig" 648 649config KVM_GUEST 650 bool "KVM Guest support (including kvmclock)" 651 depends on PARAVIRT 652 select PARAVIRT_CLOCK 653 default y 654 ---help--- 655 This option enables various optimizations for running under the KVM 656 hypervisor. It includes a paravirtualized clock, so that instead 657 of relying on a PIT (or probably other) emulation by the 658 underlying device model, the host provides the guest with 659 timing infrastructure such as time of day, and system time 660 661config KVM_DEBUG_FS 662 bool "Enable debug information for KVM Guests in debugfs" 663 depends on KVM_GUEST && DEBUG_FS 664 default n 665 ---help--- 666 This option enables collection of various statistics for KVM guest. 667 Statistics are displayed in debugfs filesystem. Enabling this option 668 may incur significant overhead. 669 670source "arch/x86/lguest/Kconfig" 671 672config PARAVIRT_TIME_ACCOUNTING 673 bool "Paravirtual steal time accounting" 674 depends on PARAVIRT 675 default n 676 ---help--- 677 Select this option to enable fine granularity task steal time 678 accounting. Time spent executing other tasks in parallel with 679 the current vCPU is discounted from the vCPU power. To account for 680 that, there can be a small performance impact. 681 682 If in doubt, say N here. 683 684config PARAVIRT_CLOCK 685 bool 686 687endif #HYPERVISOR_GUEST 688 689config NO_BOOTMEM 690 def_bool y 691 692config MEMTEST 693 bool "Memtest" 694 ---help--- 695 This option adds a kernel parameter 'memtest', which allows memtest 696 to be set. 697 memtest=0, mean disabled; -- default 698 memtest=1, mean do 1 test pattern; 699 ... 700 memtest=4, mean do 4 test patterns. 701 If you are unsure how to answer this question, answer N. 702 703config X86_SUMMIT_NUMA 704 def_bool y 705 depends on X86_32 && NUMA && X86_32_NON_STANDARD 706 707config X86_CYCLONE_TIMER 708 def_bool y 709 depends on X86_SUMMIT 710 711source "arch/x86/Kconfig.cpu" 712 713config HPET_TIMER 714 def_bool X86_64 715 prompt "HPET Timer Support" if X86_32 716 ---help--- 717 Use the IA-PC HPET (High Precision Event Timer) to manage 718 time in preference to the PIT and RTC, if a HPET is 719 present. 720 HPET is the next generation timer replacing legacy 8254s. 721 The HPET provides a stable time base on SMP 722 systems, unlike the TSC, but it is more expensive to access, 723 as it is off-chip. You can find the HPET spec at 724 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>. 725 726 You can safely choose Y here. However, HPET will only be 727 activated if the platform and the BIOS support this feature. 728 Otherwise the 8254 will be used for timing services. 729 730 Choose N to continue using the legacy 8254 timer. 731 732config HPET_EMULATE_RTC 733 def_bool y 734 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) 735 736config APB_TIMER 737 def_bool y if X86_INTEL_MID 738 prompt "Intel MID APB Timer Support" if X86_INTEL_MID 739 select DW_APB_TIMER 740 depends on X86_INTEL_MID && SFI 741 help 742 APB timer is the replacement for 8254, HPET on X86 MID platforms. 743 The APBT provides a stable time base on SMP 744 systems, unlike the TSC, but it is more expensive to access, 745 as it is off-chip. APB timers are always running regardless of CPU 746 C states, they are used as per CPU clockevent device when possible. 747 748# Mark as expert because too many people got it wrong. 749# The code disables itself when not needed. 750config DMI 751 default y 752 bool "Enable DMI scanning" if EXPERT 753 ---help--- 754 Enabled scanning of DMI to identify machine quirks. Say Y 755 here unless you have verified that your setup is not 756 affected by entries in the DMI blacklist. Required by PNP 757 BIOS code. 758 759config GART_IOMMU 760 bool "GART IOMMU support" if EXPERT 761 default y 762 select SWIOTLB 763 depends on X86_64 && PCI && AMD_NB 764 ---help--- 765 Support for full DMA access of devices with 32bit memory access only 766 on systems with more than 3GB. This is usually needed for USB, 767 sound, many IDE/SATA chipsets and some other devices. 768 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART 769 based hardware IOMMU and a software bounce buffer based IOMMU used 770 on Intel systems and as fallback. 771 The code is only active when needed (enough memory and limited 772 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified 773 too. 774 775config CALGARY_IOMMU 776 bool "IBM Calgary IOMMU support" 777 select SWIOTLB 778 depends on X86_64 && PCI 779 ---help--- 780 Support for hardware IOMMUs in IBM's xSeries x366 and x460 781 systems. Needed to run systems with more than 3GB of memory 782 properly with 32-bit PCI devices that do not support DAC 783 (Double Address Cycle). Calgary also supports bus level 784 isolation, where all DMAs pass through the IOMMU. This 785 prevents them from going anywhere except their intended 786 destination. This catches hard-to-find kernel bugs and 787 mis-behaving drivers and devices that do not use the DMA-API 788 properly to set up their DMA buffers. The IOMMU can be 789 turned off at boot time with the iommu=off parameter. 790 Normally the kernel will make the right choice by itself. 791 If unsure, say Y. 792 793config CALGARY_IOMMU_ENABLED_BY_DEFAULT 794 def_bool y 795 prompt "Should Calgary be enabled by default?" 796 depends on CALGARY_IOMMU 797 ---help--- 798 Should Calgary be enabled by default? if you choose 'y', Calgary 799 will be used (if it exists). If you choose 'n', Calgary will not be 800 used even if it exists. If you choose 'n' and would like to use 801 Calgary anyway, pass 'iommu=calgary' on the kernel command line. 802 If unsure, say Y. 803 804# need this always selected by IOMMU for the VIA workaround 805config SWIOTLB 806 def_bool y if X86_64 807 ---help--- 808 Support for software bounce buffers used on x86-64 systems 809 which don't have a hardware IOMMU. Using this PCI devices 810 which can only access 32-bits of memory can be used on systems 811 with more than 3 GB of memory. 812 If unsure, say Y. 813 814config IOMMU_HELPER 815 def_bool y 816 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU 817 818config MAXSMP 819 bool "Enable Maximum number of SMP Processors and NUMA Nodes" 820 depends on X86_64 && SMP && DEBUG_KERNEL 821 select CPUMASK_OFFSTACK 822 ---help--- 823 Enable maximum number of CPUS and NUMA Nodes for this architecture. 824 If unsure, say N. 825 826config NR_CPUS 827 int "Maximum number of CPUs" if SMP && !MAXSMP 828 range 2 8 if SMP && X86_32 && !X86_BIGSMP 829 range 2 512 if SMP && !MAXSMP 830 default "1" if !SMP 831 default "4096" if MAXSMP 832 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000) 833 default "8" if SMP 834 ---help--- 835 This allows you to specify the maximum number of CPUs which this 836 kernel will support. The maximum supported value is 512 and the 837 minimum value which makes sense is 2. 838 839 This is purely to save memory - each supported CPU adds 840 approximately eight kilobytes to the kernel image. 841 842config SCHED_SMT 843 bool "SMT (Hyperthreading) scheduler support" 844 depends on X86_HT 845 ---help--- 846 SMT scheduler support improves the CPU scheduler's decision making 847 when dealing with Intel Pentium 4 chips with HyperThreading at a 848 cost of slightly increased overhead in some places. If unsure say 849 N here. 850 851config SCHED_MC 852 def_bool y 853 prompt "Multi-core scheduler support" 854 depends on X86_HT 855 ---help--- 856 Multi-core scheduler support improves the CPU scheduler's decision 857 making when dealing with multi-core CPU chips at a cost of slightly 858 increased overhead in some places. If unsure say N here. 859 860source "kernel/Kconfig.preempt" 861 862config X86_UP_APIC 863 bool "Local APIC support on uniprocessors" 864 depends on X86_32 && !SMP && !X86_32_NON_STANDARD && !PCI_MSI 865 ---help--- 866 A local APIC (Advanced Programmable Interrupt Controller) is an 867 integrated interrupt controller in the CPU. If you have a single-CPU 868 system which has a processor with a local APIC, you can say Y here to 869 enable and use it. If you say Y here even though your machine doesn't 870 have a local APIC, then the kernel will still run with no slowdown at 871 all. The local APIC supports CPU-generated self-interrupts (timer, 872 performance counters), and the NMI watchdog which detects hard 873 lockups. 874 875config X86_UP_IOAPIC 876 bool "IO-APIC support on uniprocessors" 877 depends on X86_UP_APIC 878 ---help--- 879 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an 880 SMP-capable replacement for PC-style interrupt controllers. Most 881 SMP systems and many recent uniprocessor systems have one. 882 883 If you have a single-CPU system with an IO-APIC, you can say Y here 884 to use it. If you say Y here even though your machine doesn't have 885 an IO-APIC, then the kernel will still run with no slowdown at all. 886 887config X86_LOCAL_APIC 888 def_bool y 889 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI 890 891config X86_IO_APIC 892 def_bool y 893 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC || PCI_MSI 894 895config X86_VISWS_APIC 896 def_bool y 897 depends on X86_32 && X86_VISWS 898 899config X86_REROUTE_FOR_BROKEN_BOOT_IRQS 900 bool "Reroute for broken boot IRQs" 901 depends on X86_IO_APIC 902 ---help--- 903 This option enables a workaround that fixes a source of 904 spurious interrupts. This is recommended when threaded 905 interrupt handling is used on systems where the generation of 906 superfluous "boot interrupts" cannot be disabled. 907 908 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ 909 entry in the chipset's IO-APIC is masked (as, e.g. the RT 910 kernel does during interrupt handling). On chipsets where this 911 boot IRQ generation cannot be disabled, this workaround keeps 912 the original IRQ line masked so that only the equivalent "boot 913 IRQ" is delivered to the CPUs. The workaround also tells the 914 kernel to set up the IRQ handler on the boot IRQ line. In this 915 way only one interrupt is delivered to the kernel. Otherwise 916 the spurious second interrupt may cause the kernel to bring 917 down (vital) interrupt lines. 918 919 Only affects "broken" chipsets. Interrupt sharing may be 920 increased on these systems. 921 922config X86_MCE 923 bool "Machine Check / overheating reporting" 924 default y 925 ---help--- 926 Machine Check support allows the processor to notify the 927 kernel if it detects a problem (e.g. overheating, data corruption). 928 The action the kernel takes depends on the severity of the problem, 929 ranging from warning messages to halting the machine. 930 931config X86_MCE_INTEL 932 def_bool y 933 prompt "Intel MCE features" 934 depends on X86_MCE && X86_LOCAL_APIC 935 ---help--- 936 Additional support for intel specific MCE features such as 937 the thermal monitor. 938 939config X86_MCE_AMD 940 def_bool y 941 prompt "AMD MCE features" 942 depends on X86_MCE && X86_LOCAL_APIC 943 ---help--- 944 Additional support for AMD specific MCE features such as 945 the DRAM Error Threshold. 946 947config X86_ANCIENT_MCE 948 bool "Support for old Pentium 5 / WinChip machine checks" 949 depends on X86_32 && X86_MCE 950 ---help--- 951 Include support for machine check handling on old Pentium 5 or WinChip 952 systems. These typically need to be enabled explicitely on the command 953 line. 954 955config X86_MCE_THRESHOLD 956 depends on X86_MCE_AMD || X86_MCE_INTEL 957 def_bool y 958 959config X86_MCE_INJECT 960 depends on X86_MCE 961 tristate "Machine check injector support" 962 ---help--- 963 Provide support for injecting machine checks for testing purposes. 964 If you don't know what a machine check is and you don't do kernel 965 QA it is safe to say n. 966 967config X86_THERMAL_VECTOR 968 def_bool y 969 depends on X86_MCE_INTEL 970 971config VM86 972 bool "Enable VM86 support" if EXPERT 973 default y 974 depends on X86_32 975 ---help--- 976 This option is required by programs like DOSEMU to run 16-bit legacy 977 code on X86 processors. It also may be needed by software like 978 XFree86 to initialize some video cards via BIOS. Disabling this 979 option saves about 6k. 980 981config TOSHIBA 982 tristate "Toshiba Laptop support" 983 depends on X86_32 984 ---help--- 985 This adds a driver to safely access the System Management Mode of 986 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does 987 not work on models with a Phoenix BIOS. The System Management Mode 988 is used to set the BIOS and power saving options on Toshiba portables. 989 990 For information on utilities to make use of this driver see the 991 Toshiba Linux utilities web site at: 992 <http://www.buzzard.org.uk/toshiba/>. 993 994 Say Y if you intend to run this kernel on a Toshiba portable. 995 Say N otherwise. 996 997config I8K 998 tristate "Dell laptop support" 999 select HWMON 1000 ---help--- 1001 This adds a driver to safely access the System Management Mode 1002 of the CPU on the Dell Inspiron 8000. The System Management Mode 1003 is used to read cpu temperature and cooling fan status and to 1004 control the fans on the I8K portables. 1005 1006 This driver has been tested only on the Inspiron 8000 but it may 1007 also work with other Dell laptops. You can force loading on other 1008 models by passing the parameter `force=1' to the module. Use at 1009 your own risk. 1010 1011 For information on utilities to make use of this driver see the 1012 I8K Linux utilities web site at: 1013 <http://people.debian.org/~dz/i8k/> 1014 1015 Say Y if you intend to run this kernel on a Dell Inspiron 8000. 1016 Say N otherwise. 1017 1018config X86_REBOOTFIXUPS 1019 bool "Enable X86 board specific fixups for reboot" 1020 depends on X86_32 1021 ---help--- 1022 This enables chipset and/or board specific fixups to be done 1023 in order to get reboot to work correctly. This is only needed on 1024 some combinations of hardware and BIOS. The symptom, for which 1025 this config is intended, is when reboot ends with a stalled/hung 1026 system. 1027 1028 Currently, the only fixup is for the Geode machines using 1029 CS5530A and CS5536 chipsets and the RDC R-321x SoC. 1030 1031 Say Y if you want to enable the fixup. Currently, it's safe to 1032 enable this option even if you don't need it. 1033 Say N otherwise. 1034 1035config MICROCODE 1036 tristate "CPU microcode loading support" 1037 depends on CPU_SUP_AMD || CPU_SUP_INTEL 1038 select FW_LOADER 1039 ---help--- 1040 1041 If you say Y here, you will be able to update the microcode on 1042 certain Intel and AMD processors. The Intel support is for the 1043 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, 1044 Xeon etc. The AMD support is for families 0x10 and later. You will 1045 obviously need the actual microcode binary data itself which is not 1046 shipped with the Linux kernel. 1047 1048 This option selects the general module only, you need to select 1049 at least one vendor specific module as well. 1050 1051 To compile this driver as a module, choose M here: the module 1052 will be called microcode. 1053 1054config MICROCODE_INTEL 1055 bool "Intel microcode loading support" 1056 depends on MICROCODE 1057 default MICROCODE 1058 select FW_LOADER 1059 ---help--- 1060 This options enables microcode patch loading support for Intel 1061 processors. 1062 1063 For latest news and information on obtaining all the required 1064 Intel ingredients for this driver, check: 1065 <http://www.urbanmyth.org/microcode/>. 1066 1067config MICROCODE_AMD 1068 bool "AMD microcode loading support" 1069 depends on MICROCODE 1070 select FW_LOADER 1071 ---help--- 1072 If you select this option, microcode patch loading support for AMD 1073 processors will be enabled. 1074 1075config MICROCODE_OLD_INTERFACE 1076 def_bool y 1077 depends on MICROCODE 1078 1079config MICROCODE_INTEL_LIB 1080 def_bool y 1081 depends on MICROCODE_INTEL 1082 1083config MICROCODE_INTEL_EARLY 1084 def_bool n 1085 1086config MICROCODE_AMD_EARLY 1087 def_bool n 1088 1089config MICROCODE_EARLY 1090 bool "Early load microcode" 1091 depends on MICROCODE=y && BLK_DEV_INITRD 1092 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL 1093 select MICROCODE_AMD_EARLY if MICROCODE_AMD 1094 default y 1095 help 1096 This option provides functionality to read additional microcode data 1097 at the beginning of initrd image. The data tells kernel to load 1098 microcode to CPU's as early as possible. No functional change if no 1099 microcode data is glued to the initrd, therefore it's safe to say Y. 1100 1101config X86_MSR 1102 tristate "/dev/cpu/*/msr - Model-specific register support" 1103 ---help--- 1104 This device gives privileged processes access to the x86 1105 Model-Specific Registers (MSRs). It is a character device with 1106 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. 1107 MSR accesses are directed to a specific CPU on multi-processor 1108 systems. 1109 1110config X86_CPUID 1111 tristate "/dev/cpu/*/cpuid - CPU information support" 1112 ---help--- 1113 This device gives processes access to the x86 CPUID instruction to 1114 be executed on a specific processor. It is a character device 1115 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to 1116 /dev/cpu/31/cpuid. 1117 1118choice 1119 prompt "High Memory Support" 1120 default HIGHMEM64G if X86_NUMAQ 1121 default HIGHMEM4G 1122 depends on X86_32 1123 1124config NOHIGHMEM 1125 bool "off" 1126 depends on !X86_NUMAQ 1127 ---help--- 1128 Linux can use up to 64 Gigabytes of physical memory on x86 systems. 1129 However, the address space of 32-bit x86 processors is only 4 1130 Gigabytes large. That means that, if you have a large amount of 1131 physical memory, not all of it can be "permanently mapped" by the 1132 kernel. The physical memory that's not permanently mapped is called 1133 "high memory". 1134 1135 If you are compiling a kernel which will never run on a machine with 1136 more than 1 Gigabyte total physical RAM, answer "off" here (default 1137 choice and suitable for most users). This will result in a "3GB/1GB" 1138 split: 3GB are mapped so that each process sees a 3GB virtual memory 1139 space and the remaining part of the 4GB virtual memory space is used 1140 by the kernel to permanently map as much physical memory as 1141 possible. 1142 1143 If the machine has between 1 and 4 Gigabytes physical RAM, then 1144 answer "4GB" here. 1145 1146 If more than 4 Gigabytes is used then answer "64GB" here. This 1147 selection turns Intel PAE (Physical Address Extension) mode on. 1148 PAE implements 3-level paging on IA32 processors. PAE is fully 1149 supported by Linux, PAE mode is implemented on all recent Intel 1150 processors (Pentium Pro and better). NOTE: If you say "64GB" here, 1151 then the kernel will not boot on CPUs that don't support PAE! 1152 1153 The actual amount of total physical memory will either be 1154 auto detected or can be forced by using a kernel command line option 1155 such as "mem=256M". (Try "man bootparam" or see the documentation of 1156 your boot loader (lilo or loadlin) about how to pass options to the 1157 kernel at boot time.) 1158 1159 If unsure, say "off". 1160 1161config HIGHMEM4G 1162 bool "4GB" 1163 depends on !X86_NUMAQ 1164 ---help--- 1165 Select this if you have a 32-bit processor and between 1 and 4 1166 gigabytes of physical RAM. 1167 1168config HIGHMEM64G 1169 bool "64GB" 1170 depends on !M486 1171 select X86_PAE 1172 ---help--- 1173 Select this if you have a 32-bit processor and more than 4 1174 gigabytes of physical RAM. 1175 1176endchoice 1177 1178choice 1179 prompt "Memory split" if EXPERT 1180 default VMSPLIT_3G 1181 depends on X86_32 1182 ---help--- 1183 Select the desired split between kernel and user memory. 1184 1185 If the address range available to the kernel is less than the 1186 physical memory installed, the remaining memory will be available 1187 as "high memory". Accessing high memory is a little more costly 1188 than low memory, as it needs to be mapped into the kernel first. 1189 Note that increasing the kernel address space limits the range 1190 available to user programs, making the address space there 1191 tighter. Selecting anything other than the default 3G/1G split 1192 will also likely make your kernel incompatible with binary-only 1193 kernel modules. 1194 1195 If you are not absolutely sure what you are doing, leave this 1196 option alone! 1197 1198 config VMSPLIT_3G 1199 bool "3G/1G user/kernel split" 1200 config VMSPLIT_3G_OPT 1201 depends on !X86_PAE 1202 bool "3G/1G user/kernel split (for full 1G low memory)" 1203 config VMSPLIT_2G 1204 bool "2G/2G user/kernel split" 1205 config VMSPLIT_2G_OPT 1206 depends on !X86_PAE 1207 bool "2G/2G user/kernel split (for full 2G low memory)" 1208 config VMSPLIT_1G 1209 bool "1G/3G user/kernel split" 1210endchoice 1211 1212config PAGE_OFFSET 1213 hex 1214 default 0xB0000000 if VMSPLIT_3G_OPT 1215 default 0x80000000 if VMSPLIT_2G 1216 default 0x78000000 if VMSPLIT_2G_OPT 1217 default 0x40000000 if VMSPLIT_1G 1218 default 0xC0000000 1219 depends on X86_32 1220 1221config HIGHMEM 1222 def_bool y 1223 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) 1224 1225config X86_PAE 1226 bool "PAE (Physical Address Extension) Support" 1227 depends on X86_32 && !HIGHMEM4G 1228 ---help--- 1229 PAE is required for NX support, and furthermore enables 1230 larger swapspace support for non-overcommit purposes. It 1231 has the cost of more pagetable lookup overhead, and also 1232 consumes more pagetable space per process. 1233 1234config ARCH_PHYS_ADDR_T_64BIT 1235 def_bool y 1236 depends on X86_64 || X86_PAE 1237 1238config ARCH_DMA_ADDR_T_64BIT 1239 def_bool y 1240 depends on X86_64 || HIGHMEM64G 1241 1242config DIRECT_GBPAGES 1243 bool "Enable 1GB pages for kernel pagetables" if EXPERT 1244 default y 1245 depends on X86_64 1246 ---help--- 1247 Allow the kernel linear mapping to use 1GB pages on CPUs that 1248 support it. This can improve the kernel's performance a tiny bit by 1249 reducing TLB pressure. If in doubt, say "Y". 1250 1251# Common NUMA Features 1252config NUMA 1253 bool "Numa Memory Allocation and Scheduler Support" 1254 depends on SMP 1255 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI)) 1256 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP) 1257 ---help--- 1258 Enable NUMA (Non Uniform Memory Access) support. 1259 1260 The kernel will try to allocate memory used by a CPU on the 1261 local memory controller of the CPU and add some more 1262 NUMA awareness to the kernel. 1263 1264 For 64-bit this is recommended if the system is Intel Core i7 1265 (or later), AMD Opteron, or EM64T NUMA. 1266 1267 For 32-bit this is only needed on (rare) 32-bit-only platforms 1268 that support NUMA topologies, such as NUMAQ / Summit, or if you 1269 boot a 32-bit kernel on a 64-bit NUMA platform. 1270 1271 Otherwise, you should say N. 1272 1273comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI" 1274 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI) 1275 1276config AMD_NUMA 1277 def_bool y 1278 prompt "Old style AMD Opteron NUMA detection" 1279 depends on X86_64 && NUMA && PCI 1280 ---help--- 1281 Enable AMD NUMA node topology detection. You should say Y here if 1282 you have a multi processor AMD system. This uses an old method to 1283 read the NUMA configuration directly from the builtin Northbridge 1284 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, 1285 which also takes priority if both are compiled in. 1286 1287config X86_64_ACPI_NUMA 1288 def_bool y 1289 prompt "ACPI NUMA detection" 1290 depends on X86_64 && NUMA && ACPI && PCI 1291 select ACPI_NUMA 1292 ---help--- 1293 Enable ACPI SRAT based node topology detection. 1294 1295# Some NUMA nodes have memory ranges that span 1296# other nodes. Even though a pfn is valid and 1297# between a node's start and end pfns, it may not 1298# reside on that node. See memmap_init_zone() 1299# for details. 1300config NODES_SPAN_OTHER_NODES 1301 def_bool y 1302 depends on X86_64_ACPI_NUMA 1303 1304config NUMA_EMU 1305 bool "NUMA emulation" 1306 depends on NUMA 1307 ---help--- 1308 Enable NUMA emulation. A flat machine will be split 1309 into virtual nodes when booted with "numa=fake=N", where N is the 1310 number of nodes. This is only useful for debugging. 1311 1312config NODES_SHIFT 1313 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP 1314 range 1 10 1315 default "10" if MAXSMP 1316 default "6" if X86_64 1317 default "4" if X86_NUMAQ 1318 default "3" 1319 depends on NEED_MULTIPLE_NODES 1320 ---help--- 1321 Specify the maximum number of NUMA Nodes available on the target 1322 system. Increases memory reserved to accommodate various tables. 1323 1324config ARCH_HAVE_MEMORY_PRESENT 1325 def_bool y 1326 depends on X86_32 && DISCONTIGMEM 1327 1328config NEED_NODE_MEMMAP_SIZE 1329 def_bool y 1330 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM) 1331 1332config ARCH_FLATMEM_ENABLE 1333 def_bool y 1334 depends on X86_32 && !NUMA 1335 1336config ARCH_DISCONTIGMEM_ENABLE 1337 def_bool y 1338 depends on NUMA && X86_32 1339 1340config ARCH_DISCONTIGMEM_DEFAULT 1341 def_bool y 1342 depends on NUMA && X86_32 1343 1344config ARCH_SPARSEMEM_ENABLE 1345 def_bool y 1346 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD 1347 select SPARSEMEM_STATIC if X86_32 1348 select SPARSEMEM_VMEMMAP_ENABLE if X86_64 1349 1350config ARCH_SPARSEMEM_DEFAULT 1351 def_bool y 1352 depends on X86_64 1353 1354config ARCH_SELECT_MEMORY_MODEL 1355 def_bool y 1356 depends on ARCH_SPARSEMEM_ENABLE 1357 1358config ARCH_MEMORY_PROBE 1359 bool "Enable sysfs memory/probe interface" 1360 depends on X86_64 && MEMORY_HOTPLUG 1361 help 1362 This option enables a sysfs memory/probe interface for testing. 1363 See Documentation/memory-hotplug.txt for more information. 1364 If you are unsure how to answer this question, answer N. 1365 1366config ARCH_PROC_KCORE_TEXT 1367 def_bool y 1368 depends on X86_64 && PROC_KCORE 1369 1370config ILLEGAL_POINTER_VALUE 1371 hex 1372 default 0 if X86_32 1373 default 0xdead000000000000 if X86_64 1374 1375source "mm/Kconfig" 1376 1377config HIGHPTE 1378 bool "Allocate 3rd-level pagetables from highmem" 1379 depends on HIGHMEM 1380 ---help--- 1381 The VM uses one page table entry for each page of physical memory. 1382 For systems with a lot of RAM, this can be wasteful of precious 1383 low memory. Setting this option will put user-space page table 1384 entries in high memory. 1385 1386config X86_CHECK_BIOS_CORRUPTION 1387 bool "Check for low memory corruption" 1388 ---help--- 1389 Periodically check for memory corruption in low memory, which 1390 is suspected to be caused by BIOS. Even when enabled in the 1391 configuration, it is disabled at runtime. Enable it by 1392 setting "memory_corruption_check=1" on the kernel command 1393 line. By default it scans the low 64k of memory every 60 1394 seconds; see the memory_corruption_check_size and 1395 memory_corruption_check_period parameters in 1396 Documentation/kernel-parameters.txt to adjust this. 1397 1398 When enabled with the default parameters, this option has 1399 almost no overhead, as it reserves a relatively small amount 1400 of memory and scans it infrequently. It both detects corruption 1401 and prevents it from affecting the running system. 1402 1403 It is, however, intended as a diagnostic tool; if repeatable 1404 BIOS-originated corruption always affects the same memory, 1405 you can use memmap= to prevent the kernel from using that 1406 memory. 1407 1408config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK 1409 bool "Set the default setting of memory_corruption_check" 1410 depends on X86_CHECK_BIOS_CORRUPTION 1411 default y 1412 ---help--- 1413 Set whether the default state of memory_corruption_check is 1414 on or off. 1415 1416config X86_RESERVE_LOW 1417 int "Amount of low memory, in kilobytes, to reserve for the BIOS" 1418 default 64 1419 range 4 640 1420 ---help--- 1421 Specify the amount of low memory to reserve for the BIOS. 1422 1423 The first page contains BIOS data structures that the kernel 1424 must not use, so that page must always be reserved. 1425 1426 By default we reserve the first 64K of physical RAM, as a 1427 number of BIOSes are known to corrupt that memory range 1428 during events such as suspend/resume or monitor cable 1429 insertion, so it must not be used by the kernel. 1430 1431 You can set this to 4 if you are absolutely sure that you 1432 trust the BIOS to get all its memory reservations and usages 1433 right. If you know your BIOS have problems beyond the 1434 default 64K area, you can set this to 640 to avoid using the 1435 entire low memory range. 1436 1437 If you have doubts about the BIOS (e.g. suspend/resume does 1438 not work or there's kernel crashes after certain hardware 1439 hotplug events) then you might want to enable 1440 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check 1441 typical corruption patterns. 1442 1443 Leave this to the default value of 64 if you are unsure. 1444 1445config MATH_EMULATION 1446 bool 1447 prompt "Math emulation" if X86_32 1448 ---help--- 1449 Linux can emulate a math coprocessor (used for floating point 1450 operations) if you don't have one. 486DX and Pentium processors have 1451 a math coprocessor built in, 486SX and 386 do not, unless you added 1452 a 487DX or 387, respectively. (The messages during boot time can 1453 give you some hints here ["man dmesg"].) Everyone needs either a 1454 coprocessor or this emulation. 1455 1456 If you don't have a math coprocessor, you need to say Y here; if you 1457 say Y here even though you have a coprocessor, the coprocessor will 1458 be used nevertheless. (This behavior can be changed with the kernel 1459 command line option "no387", which comes handy if your coprocessor 1460 is broken. Try "man bootparam" or see the documentation of your boot 1461 loader (lilo or loadlin) about how to pass options to the kernel at 1462 boot time.) This means that it is a good idea to say Y here if you 1463 intend to use this kernel on different machines. 1464 1465 More information about the internals of the Linux math coprocessor 1466 emulation can be found in <file:arch/x86/math-emu/README>. 1467 1468 If you are not sure, say Y; apart from resulting in a 66 KB bigger 1469 kernel, it won't hurt. 1470 1471config MTRR 1472 def_bool y 1473 prompt "MTRR (Memory Type Range Register) support" if EXPERT 1474 ---help--- 1475 On Intel P6 family processors (Pentium Pro, Pentium II and later) 1476 the Memory Type Range Registers (MTRRs) may be used to control 1477 processor access to memory ranges. This is most useful if you have 1478 a video (VGA) card on a PCI or AGP bus. Enabling write-combining 1479 allows bus write transfers to be combined into a larger transfer 1480 before bursting over the PCI/AGP bus. This can increase performance 1481 of image write operations 2.5 times or more. Saying Y here creates a 1482 /proc/mtrr file which may be used to manipulate your processor's 1483 MTRRs. Typically the X server should use this. 1484 1485 This code has a reasonably generic interface so that similar 1486 control registers on other processors can be easily supported 1487 as well: 1488 1489 The Cyrix 6x86, 6x86MX and M II processors have Address Range 1490 Registers (ARRs) which provide a similar functionality to MTRRs. For 1491 these, the ARRs are used to emulate the MTRRs. 1492 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two 1493 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing 1494 write-combining. All of these processors are supported by this code 1495 and it makes sense to say Y here if you have one of them. 1496 1497 Saying Y here also fixes a problem with buggy SMP BIOSes which only 1498 set the MTRRs for the boot CPU and not for the secondary CPUs. This 1499 can lead to all sorts of problems, so it's good to say Y here. 1500 1501 You can safely say Y even if your machine doesn't have MTRRs, you'll 1502 just add about 9 KB to your kernel. 1503 1504 See <file:Documentation/x86/mtrr.txt> for more information. 1505 1506config MTRR_SANITIZER 1507 def_bool y 1508 prompt "MTRR cleanup support" 1509 depends on MTRR 1510 ---help--- 1511 Convert MTRR layout from continuous to discrete, so X drivers can 1512 add writeback entries. 1513 1514 Can be disabled with disable_mtrr_cleanup on the kernel command line. 1515 The largest mtrr entry size for a continuous block can be set with 1516 mtrr_chunk_size. 1517 1518 If unsure, say Y. 1519 1520config MTRR_SANITIZER_ENABLE_DEFAULT 1521 int "MTRR cleanup enable value (0-1)" 1522 range 0 1 1523 default "0" 1524 depends on MTRR_SANITIZER 1525 ---help--- 1526 Enable mtrr cleanup default value 1527 1528config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT 1529 int "MTRR cleanup spare reg num (0-7)" 1530 range 0 7 1531 default "1" 1532 depends on MTRR_SANITIZER 1533 ---help--- 1534 mtrr cleanup spare entries default, it can be changed via 1535 mtrr_spare_reg_nr=N on the kernel command line. 1536 1537config X86_PAT 1538 def_bool y 1539 prompt "x86 PAT support" if EXPERT 1540 depends on MTRR 1541 ---help--- 1542 Use PAT attributes to setup page level cache control. 1543 1544 PATs are the modern equivalents of MTRRs and are much more 1545 flexible than MTRRs. 1546 1547 Say N here if you see bootup problems (boot crash, boot hang, 1548 spontaneous reboots) or a non-working video driver. 1549 1550 If unsure, say Y. 1551 1552config ARCH_USES_PG_UNCACHED 1553 def_bool y 1554 depends on X86_PAT 1555 1556config ARCH_RANDOM 1557 def_bool y 1558 prompt "x86 architectural random number generator" if EXPERT 1559 ---help--- 1560 Enable the x86 architectural RDRAND instruction 1561 (Intel Bull Mountain technology) to generate random numbers. 1562 If supported, this is a high bandwidth, cryptographically 1563 secure hardware random number generator. 1564 1565config X86_SMAP 1566 def_bool y 1567 prompt "Supervisor Mode Access Prevention" if EXPERT 1568 ---help--- 1569 Supervisor Mode Access Prevention (SMAP) is a security 1570 feature in newer Intel processors. There is a small 1571 performance cost if this enabled and turned on; there is 1572 also a small increase in the kernel size if this is enabled. 1573 1574 If unsure, say Y. 1575 1576config EFI 1577 bool "EFI runtime service support" 1578 depends on ACPI 1579 select UCS2_STRING 1580 ---help--- 1581 This enables the kernel to use EFI runtime services that are 1582 available (such as the EFI variable services). 1583 1584 This option is only useful on systems that have EFI firmware. 1585 In addition, you should use the latest ELILO loader available 1586 at <http://elilo.sourceforge.net> in order to take advantage 1587 of EFI runtime services. However, even with this option, the 1588 resultant kernel should continue to boot on existing non-EFI 1589 platforms. 1590 1591config EFI_STUB 1592 bool "EFI stub support" 1593 depends on EFI 1594 ---help--- 1595 This kernel feature allows a bzImage to be loaded directly 1596 by EFI firmware without the use of a bootloader. 1597 1598 See Documentation/x86/efi-stub.txt for more information. 1599 1600config SECCOMP 1601 def_bool y 1602 prompt "Enable seccomp to safely compute untrusted bytecode" 1603 ---help--- 1604 This kernel feature is useful for number crunching applications 1605 that may need to compute untrusted bytecode during their 1606 execution. By using pipes or other transports made available to 1607 the process as file descriptors supporting the read/write 1608 syscalls, it's possible to isolate those applications in 1609 their own address space using seccomp. Once seccomp is 1610 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 1611 and the task is only allowed to execute a few safe syscalls 1612 defined by each seccomp mode. 1613 1614 If unsure, say Y. Only embedded should say N here. 1615 1616config CC_STACKPROTECTOR 1617 bool "Enable -fstack-protector buffer overflow detection" 1618 ---help--- 1619 This option turns on the -fstack-protector GCC feature. This 1620 feature puts, at the beginning of functions, a canary value on 1621 the stack just before the return address, and validates 1622 the value just before actually returning. Stack based buffer 1623 overflows (that need to overwrite this return address) now also 1624 overwrite the canary, which gets detected and the attack is then 1625 neutralized via a kernel panic. 1626 1627 This feature requires gcc version 4.2 or above, or a distribution 1628 gcc with the feature backported. Older versions are automatically 1629 detected and for those versions, this configuration option is 1630 ignored. (and a warning is printed during bootup) 1631 1632source kernel/Kconfig.hz 1633 1634config KEXEC 1635 bool "kexec system call" 1636 ---help--- 1637 kexec is a system call that implements the ability to shutdown your 1638 current kernel, and to start another kernel. It is like a reboot 1639 but it is independent of the system firmware. And like a reboot 1640 you can start any kernel with it, not just Linux. 1641 1642 The name comes from the similarity to the exec system call. 1643 1644 It is an ongoing process to be certain the hardware in a machine 1645 is properly shutdown, so do not be surprised if this code does not 1646 initially work for you. As of this writing the exact hardware 1647 interface is strongly in flux, so no good recommendation can be 1648 made. 1649 1650config CRASH_DUMP 1651 bool "kernel crash dumps" 1652 depends on X86_64 || (X86_32 && HIGHMEM) 1653 ---help--- 1654 Generate crash dump after being started by kexec. 1655 This should be normally only set in special crash dump kernels 1656 which are loaded in the main kernel with kexec-tools into 1657 a specially reserved region and then later executed after 1658 a crash by kdump/kexec. The crash dump kernel must be compiled 1659 to a memory address not used by the main kernel or BIOS using 1660 PHYSICAL_START, or it must be built as a relocatable image 1661 (CONFIG_RELOCATABLE=y). 1662 For more details see Documentation/kdump/kdump.txt 1663 1664config KEXEC_JUMP 1665 bool "kexec jump" 1666 depends on KEXEC && HIBERNATION 1667 ---help--- 1668 Jump between original kernel and kexeced kernel and invoke 1669 code in physical address mode via KEXEC 1670 1671config PHYSICAL_START 1672 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) 1673 default "0x1000000" 1674 ---help--- 1675 This gives the physical address where the kernel is loaded. 1676 1677 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then 1678 bzImage will decompress itself to above physical address and 1679 run from there. Otherwise, bzImage will run from the address where 1680 it has been loaded by the boot loader and will ignore above physical 1681 address. 1682 1683 In normal kdump cases one does not have to set/change this option 1684 as now bzImage can be compiled as a completely relocatable image 1685 (CONFIG_RELOCATABLE=y) and be used to load and run from a different 1686 address. This option is mainly useful for the folks who don't want 1687 to use a bzImage for capturing the crash dump and want to use a 1688 vmlinux instead. vmlinux is not relocatable hence a kernel needs 1689 to be specifically compiled to run from a specific memory area 1690 (normally a reserved region) and this option comes handy. 1691 1692 So if you are using bzImage for capturing the crash dump, 1693 leave the value here unchanged to 0x1000000 and set 1694 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux 1695 for capturing the crash dump change this value to start of 1696 the reserved region. In other words, it can be set based on 1697 the "X" value as specified in the "crashkernel=YM@XM" 1698 command line boot parameter passed to the panic-ed 1699 kernel. Please take a look at Documentation/kdump/kdump.txt 1700 for more details about crash dumps. 1701 1702 Usage of bzImage for capturing the crash dump is recommended as 1703 one does not have to build two kernels. Same kernel can be used 1704 as production kernel and capture kernel. Above option should have 1705 gone away after relocatable bzImage support is introduced. But it 1706 is present because there are users out there who continue to use 1707 vmlinux for dump capture. This option should go away down the 1708 line. 1709 1710 Don't change this unless you know what you are doing. 1711 1712config RELOCATABLE 1713 bool "Build a relocatable kernel" 1714 default y 1715 ---help--- 1716 This builds a kernel image that retains relocation information 1717 so it can be loaded someplace besides the default 1MB. 1718 The relocations tend to make the kernel binary about 10% larger, 1719 but are discarded at runtime. 1720 1721 One use is for the kexec on panic case where the recovery kernel 1722 must live at a different physical address than the primary 1723 kernel. 1724 1725 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address 1726 it has been loaded at and the compile time physical address 1727 (CONFIG_PHYSICAL_START) is ignored. 1728 1729# Relocation on x86-32 needs some additional build support 1730config X86_NEED_RELOCS 1731 def_bool y 1732 depends on X86_32 && RELOCATABLE 1733 1734config PHYSICAL_ALIGN 1735 hex "Alignment value to which kernel should be aligned" 1736 default "0x1000000" 1737 range 0x2000 0x1000000 if X86_32 1738 range 0x200000 0x1000000 if X86_64 1739 ---help--- 1740 This value puts the alignment restrictions on physical address 1741 where kernel is loaded and run from. Kernel is compiled for an 1742 address which meets above alignment restriction. 1743 1744 If bootloader loads the kernel at a non-aligned address and 1745 CONFIG_RELOCATABLE is set, kernel will move itself to nearest 1746 address aligned to above value and run from there. 1747 1748 If bootloader loads the kernel at a non-aligned address and 1749 CONFIG_RELOCATABLE is not set, kernel will ignore the run time 1750 load address and decompress itself to the address it has been 1751 compiled for and run from there. The address for which kernel is 1752 compiled already meets above alignment restrictions. Hence the 1753 end result is that kernel runs from a physical address meeting 1754 above alignment restrictions. 1755 1756 On 32-bit this value must be a multiple of 0x2000. On 64-bit 1757 this value must be a multiple of 0x200000. 1758 1759 Don't change this unless you know what you are doing. 1760 1761config HOTPLUG_CPU 1762 bool "Support for hot-pluggable CPUs" 1763 depends on SMP 1764 ---help--- 1765 Say Y here to allow turning CPUs off and on. CPUs can be 1766 controlled through /sys/devices/system/cpu. 1767 ( Note: power management support will enable this option 1768 automatically on SMP systems. ) 1769 Say N if you want to disable CPU hotplug. 1770 1771config BOOTPARAM_HOTPLUG_CPU0 1772 bool "Set default setting of cpu0_hotpluggable" 1773 default n 1774 depends on HOTPLUG_CPU 1775 ---help--- 1776 Set whether default state of cpu0_hotpluggable is on or off. 1777 1778 Say Y here to enable CPU0 hotplug by default. If this switch 1779 is turned on, there is no need to give cpu0_hotplug kernel 1780 parameter and the CPU0 hotplug feature is enabled by default. 1781 1782 Please note: there are two known CPU0 dependencies if you want 1783 to enable the CPU0 hotplug feature either by this switch or by 1784 cpu0_hotplug kernel parameter. 1785 1786 First, resume from hibernate or suspend always starts from CPU0. 1787 So hibernate and suspend are prevented if CPU0 is offline. 1788 1789 Second dependency is PIC interrupts always go to CPU0. CPU0 can not 1790 offline if any interrupt can not migrate out of CPU0. There may 1791 be other CPU0 dependencies. 1792 1793 Please make sure the dependencies are under your control before 1794 you enable this feature. 1795 1796 Say N if you don't want to enable CPU0 hotplug feature by default. 1797 You still can enable the CPU0 hotplug feature at boot by kernel 1798 parameter cpu0_hotplug. 1799 1800config DEBUG_HOTPLUG_CPU0 1801 def_bool n 1802 prompt "Debug CPU0 hotplug" 1803 depends on HOTPLUG_CPU 1804 ---help--- 1805 Enabling this option offlines CPU0 (if CPU0 can be offlined) as 1806 soon as possible and boots up userspace with CPU0 offlined. User 1807 can online CPU0 back after boot time. 1808 1809 To debug CPU0 hotplug, you need to enable CPU0 offline/online 1810 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during 1811 compilation or giving cpu0_hotplug kernel parameter at boot. 1812 1813 If unsure, say N. 1814 1815config COMPAT_VDSO 1816 def_bool y 1817 prompt "Compat VDSO support" 1818 depends on X86_32 || IA32_EMULATION 1819 ---help--- 1820 Map the 32-bit VDSO to the predictable old-style address too. 1821 1822 Say N here if you are running a sufficiently recent glibc 1823 version (2.3.3 or later), to remove the high-mapped 1824 VDSO mapping and to exclusively use the randomized VDSO. 1825 1826 If unsure, say Y. 1827 1828config CMDLINE_BOOL 1829 bool "Built-in kernel command line" 1830 ---help--- 1831 Allow for specifying boot arguments to the kernel at 1832 build time. On some systems (e.g. embedded ones), it is 1833 necessary or convenient to provide some or all of the 1834 kernel boot arguments with the kernel itself (that is, 1835 to not rely on the boot loader to provide them.) 1836 1837 To compile command line arguments into the kernel, 1838 set this option to 'Y', then fill in the 1839 the boot arguments in CONFIG_CMDLINE. 1840 1841 Systems with fully functional boot loaders (i.e. non-embedded) 1842 should leave this option set to 'N'. 1843 1844config CMDLINE 1845 string "Built-in kernel command string" 1846 depends on CMDLINE_BOOL 1847 default "" 1848 ---help--- 1849 Enter arguments here that should be compiled into the kernel 1850 image and used at boot time. If the boot loader provides a 1851 command line at boot time, it is appended to this string to 1852 form the full kernel command line, when the system boots. 1853 1854 However, you can use the CONFIG_CMDLINE_OVERRIDE option to 1855 change this behavior. 1856 1857 In most cases, the command line (whether built-in or provided 1858 by the boot loader) should specify the device for the root 1859 file system. 1860 1861config CMDLINE_OVERRIDE 1862 bool "Built-in command line overrides boot loader arguments" 1863 depends on CMDLINE_BOOL 1864 ---help--- 1865 Set this option to 'Y' to have the kernel ignore the boot loader 1866 command line, and use ONLY the built-in command line. 1867 1868 This is used to work around broken boot loaders. This should 1869 be set to 'N' under normal conditions. 1870 1871endmenu 1872 1873config ARCH_ENABLE_MEMORY_HOTPLUG 1874 def_bool y 1875 depends on X86_64 || (X86_32 && HIGHMEM) 1876 1877config ARCH_ENABLE_MEMORY_HOTREMOVE 1878 def_bool y 1879 depends on MEMORY_HOTPLUG 1880 1881config USE_PERCPU_NUMA_NODE_ID 1882 def_bool y 1883 depends on NUMA 1884 1885menu "Power management and ACPI options" 1886 1887config ARCH_HIBERNATION_HEADER 1888 def_bool y 1889 depends on X86_64 && HIBERNATION 1890 1891source "kernel/power/Kconfig" 1892 1893source "drivers/acpi/Kconfig" 1894 1895source "drivers/sfi/Kconfig" 1896 1897config X86_APM_BOOT 1898 def_bool y 1899 depends on APM 1900 1901menuconfig APM 1902 tristate "APM (Advanced Power Management) BIOS support" 1903 depends on X86_32 && PM_SLEEP 1904 ---help--- 1905 APM is a BIOS specification for saving power using several different 1906 techniques. This is mostly useful for battery powered laptops with 1907 APM compliant BIOSes. If you say Y here, the system time will be 1908 reset after a RESUME operation, the /proc/apm device will provide 1909 battery status information, and user-space programs will receive 1910 notification of APM "events" (e.g. battery status change). 1911 1912 If you select "Y" here, you can disable actual use of the APM 1913 BIOS by passing the "apm=off" option to the kernel at boot time. 1914 1915 Note that the APM support is almost completely disabled for 1916 machines with more than one CPU. 1917 1918 In order to use APM, you will need supporting software. For location 1919 and more information, read <file:Documentation/power/apm-acpi.txt> 1920 and the Battery Powered Linux mini-HOWTO, available from 1921 <http://www.tldp.org/docs.html#howto>. 1922 1923 This driver does not spin down disk drives (see the hdparm(8) 1924 manpage ("man 8 hdparm") for that), and it doesn't turn off 1925 VESA-compliant "green" monitors. 1926 1927 This driver does not support the TI 4000M TravelMate and the ACER 1928 486/DX4/75 because they don't have compliant BIOSes. Many "green" 1929 desktop machines also don't have compliant BIOSes, and this driver 1930 may cause those machines to panic during the boot phase. 1931 1932 Generally, if you don't have a battery in your machine, there isn't 1933 much point in using this driver and you should say N. If you get 1934 random kernel OOPSes or reboots that don't seem to be related to 1935 anything, try disabling/enabling this option (or disabling/enabling 1936 APM in your BIOS). 1937 1938 Some other things you should try when experiencing seemingly random, 1939 "weird" problems: 1940 1941 1) make sure that you have enough swap space and that it is 1942 enabled. 1943 2) pass the "no-hlt" option to the kernel 1944 3) switch on floating point emulation in the kernel and pass 1945 the "no387" option to the kernel 1946 4) pass the "floppy=nodma" option to the kernel 1947 5) pass the "mem=4M" option to the kernel (thereby disabling 1948 all but the first 4 MB of RAM) 1949 6) make sure that the CPU is not over clocked. 1950 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> 1951 8) disable the cache from your BIOS settings 1952 9) install a fan for the video card or exchange video RAM 1953 10) install a better fan for the CPU 1954 11) exchange RAM chips 1955 12) exchange the motherboard. 1956 1957 To compile this driver as a module, choose M here: the 1958 module will be called apm. 1959 1960if APM 1961 1962config APM_IGNORE_USER_SUSPEND 1963 bool "Ignore USER SUSPEND" 1964 ---help--- 1965 This option will ignore USER SUSPEND requests. On machines with a 1966 compliant APM BIOS, you want to say N. However, on the NEC Versa M 1967 series notebooks, it is necessary to say Y because of a BIOS bug. 1968 1969config APM_DO_ENABLE 1970 bool "Enable PM at boot time" 1971 ---help--- 1972 Enable APM features at boot time. From page 36 of the APM BIOS 1973 specification: "When disabled, the APM BIOS does not automatically 1974 power manage devices, enter the Standby State, enter the Suspend 1975 State, or take power saving steps in response to CPU Idle calls." 1976 This driver will make CPU Idle calls when Linux is idle (unless this 1977 feature is turned off -- see "Do CPU IDLE calls", below). This 1978 should always save battery power, but more complicated APM features 1979 will be dependent on your BIOS implementation. You may need to turn 1980 this option off if your computer hangs at boot time when using APM 1981 support, or if it beeps continuously instead of suspending. Turn 1982 this off if you have a NEC UltraLite Versa 33/C or a Toshiba 1983 T400CDT. This is off by default since most machines do fine without 1984 this feature. 1985 1986config APM_CPU_IDLE 1987 depends on CPU_IDLE 1988 bool "Make CPU Idle calls when idle" 1989 ---help--- 1990 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. 1991 On some machines, this can activate improved power savings, such as 1992 a slowed CPU clock rate, when the machine is idle. These idle calls 1993 are made after the idle loop has run for some length of time (e.g., 1994 333 mS). On some machines, this will cause a hang at boot time or 1995 whenever the CPU becomes idle. (On machines with more than one CPU, 1996 this option does nothing.) 1997 1998config APM_DISPLAY_BLANK 1999 bool "Enable console blanking using APM" 2000 ---help--- 2001 Enable console blanking using the APM. Some laptops can use this to 2002 turn off the LCD backlight when the screen blanker of the Linux 2003 virtual console blanks the screen. Note that this is only used by 2004 the virtual console screen blanker, and won't turn off the backlight 2005 when using the X Window system. This also doesn't have anything to 2006 do with your VESA-compliant power-saving monitor. Further, this 2007 option doesn't work for all laptops -- it might not turn off your 2008 backlight at all, or it might print a lot of errors to the console, 2009 especially if you are using gpm. 2010 2011config APM_ALLOW_INTS 2012 bool "Allow interrupts during APM BIOS calls" 2013 ---help--- 2014 Normally we disable external interrupts while we are making calls to 2015 the APM BIOS as a measure to lessen the effects of a badly behaving 2016 BIOS implementation. The BIOS should reenable interrupts if it 2017 needs to. Unfortunately, some BIOSes do not -- especially those in 2018 many of the newer IBM Thinkpads. If you experience hangs when you 2019 suspend, try setting this to Y. Otherwise, say N. 2020 2021endif # APM 2022 2023source "drivers/cpufreq/Kconfig" 2024 2025source "drivers/cpuidle/Kconfig" 2026 2027source "drivers/idle/Kconfig" 2028 2029endmenu 2030 2031 2032menu "Bus options (PCI etc.)" 2033 2034config PCI 2035 bool "PCI support" 2036 default y 2037 ---help--- 2038 Find out whether you have a PCI motherboard. PCI is the name of a 2039 bus system, i.e. the way the CPU talks to the other stuff inside 2040 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or 2041 VESA. If you have PCI, say Y, otherwise N. 2042 2043choice 2044 prompt "PCI access mode" 2045 depends on X86_32 && PCI 2046 default PCI_GOANY 2047 ---help--- 2048 On PCI systems, the BIOS can be used to detect the PCI devices and 2049 determine their configuration. However, some old PCI motherboards 2050 have BIOS bugs and may crash if this is done. Also, some embedded 2051 PCI-based systems don't have any BIOS at all. Linux can also try to 2052 detect the PCI hardware directly without using the BIOS. 2053 2054 With this option, you can specify how Linux should detect the 2055 PCI devices. If you choose "BIOS", the BIOS will be used, 2056 if you choose "Direct", the BIOS won't be used, and if you 2057 choose "MMConfig", then PCI Express MMCONFIG will be used. 2058 If you choose "Any", the kernel will try MMCONFIG, then the 2059 direct access method and falls back to the BIOS if that doesn't 2060 work. If unsure, go with the default, which is "Any". 2061 2062config PCI_GOBIOS 2063 bool "BIOS" 2064 2065config PCI_GOMMCONFIG 2066 bool "MMConfig" 2067 2068config PCI_GODIRECT 2069 bool "Direct" 2070 2071config PCI_GOOLPC 2072 bool "OLPC XO-1" 2073 depends on OLPC 2074 2075config PCI_GOANY 2076 bool "Any" 2077 2078endchoice 2079 2080config PCI_BIOS 2081 def_bool y 2082 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) 2083 2084# x86-64 doesn't support PCI BIOS access from long mode so always go direct. 2085config PCI_DIRECT 2086 def_bool y 2087 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) 2088 2089config PCI_MMCONFIG 2090 def_bool y 2091 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY) 2092 2093config PCI_OLPC 2094 def_bool y 2095 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) 2096 2097config PCI_XEN 2098 def_bool y 2099 depends on PCI && XEN 2100 select SWIOTLB_XEN 2101 2102config PCI_DOMAINS 2103 def_bool y 2104 depends on PCI 2105 2106config PCI_MMCONFIG 2107 bool "Support mmconfig PCI config space access" 2108 depends on X86_64 && PCI && ACPI 2109 2110config PCI_CNB20LE_QUIRK 2111 bool "Read CNB20LE Host Bridge Windows" if EXPERT 2112 depends on PCI 2113 help 2114 Read the PCI windows out of the CNB20LE host bridge. This allows 2115 PCI hotplug to work on systems with the CNB20LE chipset which do 2116 not have ACPI. 2117 2118 There's no public spec for this chipset, and this functionality 2119 is known to be incomplete. 2120 2121 You should say N unless you know you need this. 2122 2123source "drivers/pci/pcie/Kconfig" 2124 2125source "drivers/pci/Kconfig" 2126 2127# x86_64 have no ISA slots, but can have ISA-style DMA. 2128config ISA_DMA_API 2129 bool "ISA-style DMA support" if (X86_64 && EXPERT) 2130 default y 2131 help 2132 Enables ISA-style DMA support for devices requiring such controllers. 2133 If unsure, say Y. 2134 2135if X86_32 2136 2137config ISA 2138 bool "ISA support" 2139 ---help--- 2140 Find out whether you have ISA slots on your motherboard. ISA is the 2141 name of a bus system, i.e. the way the CPU talks to the other stuff 2142 inside your box. Other bus systems are PCI, EISA, MicroChannel 2143 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 2144 newer boards don't support it. If you have ISA, say Y, otherwise N. 2145 2146config EISA 2147 bool "EISA support" 2148 depends on ISA 2149 ---help--- 2150 The Extended Industry Standard Architecture (EISA) bus was 2151 developed as an open alternative to the IBM MicroChannel bus. 2152 2153 The EISA bus provided some of the features of the IBM MicroChannel 2154 bus while maintaining backward compatibility with cards made for 2155 the older ISA bus. The EISA bus saw limited use between 1988 and 2156 1995 when it was made obsolete by the PCI bus. 2157 2158 Say Y here if you are building a kernel for an EISA-based machine. 2159 2160 Otherwise, say N. 2161 2162source "drivers/eisa/Kconfig" 2163 2164config SCx200 2165 tristate "NatSemi SCx200 support" 2166 ---help--- 2167 This provides basic support for National Semiconductor's 2168 (now AMD's) Geode processors. The driver probes for the 2169 PCI-IDs of several on-chip devices, so its a good dependency 2170 for other scx200_* drivers. 2171 2172 If compiled as a module, the driver is named scx200. 2173 2174config SCx200HR_TIMER 2175 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" 2176 depends on SCx200 2177 default y 2178 ---help--- 2179 This driver provides a clocksource built upon the on-chip 2180 27MHz high-resolution timer. Its also a workaround for 2181 NSC Geode SC-1100's buggy TSC, which loses time when the 2182 processor goes idle (as is done by the scheduler). The 2183 other workaround is idle=poll boot option. 2184 2185config OLPC 2186 bool "One Laptop Per Child support" 2187 depends on !X86_PAE 2188 select GPIOLIB 2189 select OF 2190 select OF_PROMTREE 2191 select IRQ_DOMAIN 2192 ---help--- 2193 Add support for detecting the unique features of the OLPC 2194 XO hardware. 2195 2196config OLPC_XO1_PM 2197 bool "OLPC XO-1 Power Management" 2198 depends on OLPC && MFD_CS5535 && PM_SLEEP 2199 select MFD_CORE 2200 ---help--- 2201 Add support for poweroff and suspend of the OLPC XO-1 laptop. 2202 2203config OLPC_XO1_RTC 2204 bool "OLPC XO-1 Real Time Clock" 2205 depends on OLPC_XO1_PM && RTC_DRV_CMOS 2206 ---help--- 2207 Add support for the XO-1 real time clock, which can be used as a 2208 programmable wakeup source. 2209 2210config OLPC_XO1_SCI 2211 bool "OLPC XO-1 SCI extras" 2212 depends on OLPC && OLPC_XO1_PM 2213 depends on INPUT=y 2214 select POWER_SUPPLY 2215 select GPIO_CS5535 2216 select MFD_CORE 2217 ---help--- 2218 Add support for SCI-based features of the OLPC XO-1 laptop: 2219 - EC-driven system wakeups 2220 - Power button 2221 - Ebook switch 2222 - Lid switch 2223 - AC adapter status updates 2224 - Battery status updates 2225 2226config OLPC_XO15_SCI 2227 bool "OLPC XO-1.5 SCI extras" 2228 depends on OLPC && ACPI 2229 select POWER_SUPPLY 2230 ---help--- 2231 Add support for SCI-based features of the OLPC XO-1.5 laptop: 2232 - EC-driven system wakeups 2233 - AC adapter status updates 2234 - Battery status updates 2235 2236config ALIX 2237 bool "PCEngines ALIX System Support (LED setup)" 2238 select GPIOLIB 2239 ---help--- 2240 This option enables system support for the PCEngines ALIX. 2241 At present this just sets up LEDs for GPIO control on 2242 ALIX2/3/6 boards. However, other system specific setup should 2243 get added here. 2244 2245 Note: You must still enable the drivers for GPIO and LED support 2246 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs 2247 2248 Note: You have to set alix.force=1 for boards with Award BIOS. 2249 2250config NET5501 2251 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" 2252 select GPIOLIB 2253 ---help--- 2254 This option enables system support for the Soekris Engineering net5501. 2255 2256config GEOS 2257 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" 2258 select GPIOLIB 2259 depends on DMI 2260 ---help--- 2261 This option enables system support for the Traverse Technologies GEOS. 2262 2263config TS5500 2264 bool "Technologic Systems TS-5500 platform support" 2265 depends on MELAN 2266 select CHECK_SIGNATURE 2267 select NEW_LEDS 2268 select LEDS_CLASS 2269 ---help--- 2270 This option enables system support for the Technologic Systems TS-5500. 2271 2272endif # X86_32 2273 2274config AMD_NB 2275 def_bool y 2276 depends on CPU_SUP_AMD && PCI 2277 2278source "drivers/pcmcia/Kconfig" 2279 2280source "drivers/pci/hotplug/Kconfig" 2281 2282config RAPIDIO 2283 tristate "RapidIO support" 2284 depends on PCI 2285 default n 2286 help 2287 If enabled this option will include drivers and the core 2288 infrastructure code to support RapidIO interconnect devices. 2289 2290source "drivers/rapidio/Kconfig" 2291 2292config X86_SYSFB 2293 bool "Mark VGA/VBE/EFI FB as generic system framebuffer" 2294 help 2295 Firmwares often provide initial graphics framebuffers so the BIOS, 2296 bootloader or kernel can show basic video-output during boot for 2297 user-guidance and debugging. Historically, x86 used the VESA BIOS 2298 Extensions and EFI-framebuffers for this, which are mostly limited 2299 to x86. 2300 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic 2301 framebuffers so the new generic system-framebuffer drivers can be 2302 used on x86. If the framebuffer is not compatible with the generic 2303 modes, it is adverticed as fallback platform framebuffer so legacy 2304 drivers like efifb, vesafb and uvesafb can pick it up. 2305 If this option is not selected, all system framebuffers are always 2306 marked as fallback platform framebuffers as usual. 2307 2308 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will 2309 not be able to pick up generic system framebuffers if this option 2310 is selected. You are highly encouraged to enable simplefb as 2311 replacement if you select this option. simplefb can correctly deal 2312 with generic system framebuffers. But you should still keep vesafb 2313 and others enabled as fallback if a system framebuffer is 2314 incompatible with simplefb. 2315 2316 If unsure, say Y. 2317 2318endmenu 2319 2320 2321menu "Executable file formats / Emulations" 2322 2323source "fs/Kconfig.binfmt" 2324 2325config IA32_EMULATION 2326 bool "IA32 Emulation" 2327 depends on X86_64 2328 select BINFMT_ELF 2329 select COMPAT_BINFMT_ELF 2330 select HAVE_UID16 2331 ---help--- 2332 Include code to run legacy 32-bit programs under a 2333 64-bit kernel. You should likely turn this on, unless you're 2334 100% sure that you don't have any 32-bit programs left. 2335 2336config IA32_AOUT 2337 tristate "IA32 a.out support" 2338 depends on IA32_EMULATION 2339 ---help--- 2340 Support old a.out binaries in the 32bit emulation. 2341 2342config X86_X32 2343 bool "x32 ABI for 64-bit mode" 2344 depends on X86_64 && IA32_EMULATION 2345 ---help--- 2346 Include code to run binaries for the x32 native 32-bit ABI 2347 for 64-bit processors. An x32 process gets access to the 2348 full 64-bit register file and wide data path while leaving 2349 pointers at 32 bits for smaller memory footprint. 2350 2351 You will need a recent binutils (2.22 or later) with 2352 elf32_x86_64 support enabled to compile a kernel with this 2353 option set. 2354 2355config COMPAT 2356 def_bool y 2357 depends on IA32_EMULATION || X86_X32 2358 select ARCH_WANT_OLD_COMPAT_IPC 2359 2360if COMPAT 2361config COMPAT_FOR_U64_ALIGNMENT 2362 def_bool y 2363 2364config SYSVIPC_COMPAT 2365 def_bool y 2366 depends on SYSVIPC 2367 2368config KEYS_COMPAT 2369 def_bool y 2370 depends on KEYS 2371endif 2372 2373endmenu 2374 2375 2376config HAVE_ATOMIC_IOMAP 2377 def_bool y 2378 depends on X86_32 2379 2380config X86_DEV_DMA_OPS 2381 bool 2382 depends on X86_64 || STA2X11 2383 2384config X86_DMA_REMAP 2385 bool 2386 depends on STA2X11 2387 2388source "net/Kconfig" 2389 2390source "drivers/Kconfig" 2391 2392source "drivers/firmware/Kconfig" 2393 2394source "fs/Kconfig" 2395 2396source "arch/x86/Kconfig.debug" 2397 2398source "security/Kconfig" 2399 2400source "crypto/Kconfig" 2401 2402source "arch/x86/kvm/Kconfig" 2403 2404source "lib/Kconfig" 2405